Case Based Pediatrics For Medical Students and ResidentsDepartment of Pediatrics, University of Hawaii John A. Burns School of MedicineChapter XX.3. Substance Abuse
Anthony P. S. Guerrero, MD
March 2002
Return to Table of Contents

This is a 16 year old female brought to the emergency room by her father, with the chief complaint that he thinks his daughter is using drugs and wants her to get treatment. The father reports that she has often been acting "high," with sleeplessness for several days in a row, unusual euphoria, pressured speech, increased activity (e.g., cleaning the bathroom), suspiciousness, and some aggressive behaviors. The pediatric resident begins to advise him that this behavior is typical of cocaine intoxication. However, with encouragement from the supervising emergency room physician, the resident gathers further history. She uses "ice," or "batu", roughly 2-3 times per week, smoking it by pipe. She obtains the drug from her friends. She admits to occasional marijuana use and weekend drinking of alcohol, without any history of blackouts, hallucinations, or incapacitating withdrawal symptoms. Although previously an above average student, she has, for the past year, been truant from school and is failing most of her classes. She has also run away from home on several occasions. She gives vague answers when asked about sexual history.

Her past medical history is otherwise negative. Family history is significant for a history of alcoholism and a possible psychotic illness. Her parents are divorced. There is no history of abuse or domestic violence.

Clinical course: Psychiatric consultation is obtained, and patient is briefly admitted involuntarily for psychiatric inpatient care. Diagnoses: Methamphetamine dependence and (via pelvic examination eventually performed by the consulting pediatrician) Chlamydia cervicitis. She is discharged to an adolescent substance abuse treatment program.

Substance use is common among adolescents in the United States (1). By the end of high school, 90% of adolescents have tried alcohol and 40% have tried an illicit substance. Among 17 to 19 year olds, the lifetime prevalence of alcohol abuse and dependence (beyond just experimentation) is 32%, while the lifetime prevalence of drug abuse and dependence is 10%. Consequently, pediatricians will often need to be involved in the evaluation and management of: substance use disorders, medical problems related to substance use, and/or other medical problems which may go under recognized or under managed in this high risk population.

Substance abuse is defined as a maladaptive pattern of substance use with clinically significant levels of impairment or distress, while substance dependence requires a substantial degree of substance use involving withdrawal, tolerance, and loss of control over use (2). Risk factors for these substance use disorders include genetic/family predisposition (e.g., with positive family history); exposure to substance use via family or peers; childhood psychiatric conditions; and poor academic performance. The dopamine reward pathway has been implicated in the pathophysiology of substance addiction (3). Contrary to what some may believe, there is no evidence that stimulant treatment of Attention Deficit Hyperactivity Disorder increases risk for substance abuse. In fact, a recent study suggests otherwise, possibly because of the benefits of treatment on behavior and academic performance (4).

Alcohol and sedatives (benzodiazepines, barbiturates, and related compounds) are grouped together because they facilitate binding of gamma amino butyric acid (GABA), an inhibitory neurotransmitter, to neurons. Benzodiazepines and barbiturates may sometimes be referred to as "downers," and are often available in pill form.

Cocaine and methamphetamine both work via an increase of catecholamines, leading to the psychiatric and general physical symptoms as described in the case above. Of interest, chronic use of methamphetamine, via toxic effects on the brain, may also result in a chronic psychotic disorder, even beyond cessation of its use. Patients who present with this syndrome may, on functional brain imaging, show a "Swiss cheese" pattern, with significant areas of hypo-functioning. These drugs may be inhaled, smoked, or (less commonly) taken intravenously.

Hallucinogens, including D-lysergic acid diethylamide (LSD) and various others (mostly from plants) exert their hallucinogenic effects via serotonin receptors. These may be administered via various routes. Of interest, "ecstasy", or 3,4-methylenedioxymethamphetamine, works via the catecholamine and serotonin systems and may produce amphetamine-like effects as well as feelings of closeness to people and sensory sensitivity. Symptoms of catecholamine excess as well as dehydration are possible complications of its acute use. This drug may be taken orally, inhaled, or injected intravenously.

Inhalants, including glue, paint thinner, and other solvents, likely cause disruption of neuronal and other cell membranes, leading to potential complications of encephalopathy and cardiac arrhythmias. These agents, being relatively accessible, may be abused by younger adolescents.

Marijuana exerts its intoxicating effects via tetrahydrocannabinoid receptors in the brain. It is most commonly smoked.

Opioids, including heroin and controlled prescription medications, working via the opioid receptors in the brain, may result in respiratory depression, miosis, analgesia, and constipation during intoxication and autonomic hyperactivity, gastrointestinal hyperactivity, and significant discomfort during withdrawal. Heroin use may be associated with any of the medical complications (e.g., HIV disease, endocarditis, localized skin infections) associated with intravenous drug use and injections using contaminated needles.

Phencyclidine, or PCP, exerts its effects via the receptor of N-methyl-D-aspartate (NMDA), an excitatory neurotransmitter, and other receptors. Intoxication may result in diminished responsiveness to pain, severe muscle rigidity, and hyperthermia. It is most commonly smoked, but may be administered via other routes as well. Because it is more rapidly excreted in acidic urine, acidifying agents may be considered in detoxification.

Other drugs: Gamma-hydroxy-butyrate, or GHB, can have the extremely serious side effects of seizures and coma. It exerts its effects via the dopamine and opioid receptors. It is often available in liquid form.

The pediatrician must always consider substance use as a possibility, and must be prepared to manage any life threatening effects of either intoxication or withdrawal. All substances can potentially cause acute allergic and/or other serious idiosyncratic reactions, which should be managed accordingly, with priority attention always given to airway, breathing, and circulation.

Intoxication with alcohol, especially in a relatively alcohol naive adolescent, may result in a life threatening respiratory depression. Hence, medical admission with close monitoring of respiratory status may be indicated. Likewise, withdrawal from alcohol or other sedatives (e.g., benzodiazepines, barbiturates) may also be life threatening, although delirium tremens is fortunately not as common in adolescents as it is in older adults. Careful monitoring of vital signs, prescription of thiamine and multivitamins, and implementation of benzodiazepine-based protocols for management of withdrawal (5) are indicated. To assess withdrawal risk, the clinician should take a careful history to include pattern/regularity of use, timing of last use, severity of past withdrawal symptoms, etc.

The autonomic hyperactivity resulting from cocaine or methamphetamine intoxication may lead to life threatening arrhythmias or ischemia of the brain, heart, or intestines. Close cardiorespiratory monitoring and an electrocardiogram may be indicated.

Acute agitation, delirium, and/or psychosis resulting from cocaine, methamphetamine, hallucinogen, or marijuana intoxication may be managed using a quiet, supportive setting and frequent reorientation to person, place, and time. Although substance use may result in altered mental status, general medical conditions (e.g., intracranial bleed) must always be ruled out, as they unfortunately do occur in youth who use substances. Benzodiazepines may be used for agitation. High potency antipsychotics (e.g., haloperidol) may be used for symptoms of delirium or psychosis with agitation. However, antipsychotics should be avoided in cases of alcohol or sedative withdrawal, as these medications may lower the seizure threshold (in such cases, benzodiazepines should be used). Low potency antipsychotics (e.g., chlorpromazine) should not be used in cases of PCP intoxication, as the additive anticholinergic effects may worsen the delirium.

Because youth with substance use disorders are often at risk for poor health, the physician should perform a careful history, physical examination, and laboratory evaluation and thoroughly address any other concerns that may be detected. In addition to addressing physical health concerns, the physician should employ the bio-psycho-social approach (discussed in the chapter on suicide and violence) to comprehensively care for the adolescent with a substance use disorder, and should have a low threshold for consulting a child and adolescent psychiatrist.

Often, the primary care physician can be a credible source of information about the long-term side effects of substance abuse, such as liver damage from alcohol use, serious "brain damage" from inhalant use, and lung cancer from tobacco or marijuana use. Also, the primary care physician may have significant familiarity with the family history, and can be helpful in "personalizing" the information for the adolescent (e.g., discussing relatives who died of medical sequelae of substance abuse or whose lives were destroyed by addiction).

Above all, physicians should be compassionate and professionally responsible towards adolescents with substance use disorders. They should recognize substance abuse as a medical condition and should respect the seriousness of its complications and co-morbidities.

Questions

1. The prevalence of alcohol abuse and dependence among 17 to 19 year olds in the United States is closest to: a) 1%, b) 10%, c) 30%, d) 50%, e) 90%

3. True/False: Death may occur during intoxication with alcohol or an illicit substance.

4. True/False: Death may occur during withdrawal from alcohol or an illicit substance.

5. Match the following substances with their associated syndromes:

a. Barbiturates

i. Severe encephalopathy

b."Ecstasy"

ii. Lung cancer

c. Inhalants

iii. Rhabdomyolysis during intoxication

d. Marijuana

iv. Wanting to touch/be touched during intoxication

e. Methamphetamine

v. Seizures during withdrawl

f. PCP

vi. "Swiss cheese" appearance on functional brain imaging

References

1. American Academy of Child and Adolescent Psychiatry. Practice Parameters for the Assessment and Treatment of Children and Adolescents with Substance Use Disorders. J Am Acad Child Adolesc Psychiatry 1997;36:140S-156S.